What is the hardest puzzle you have completed?

What is the hardest puzzle you’ve made, found, completed. Post it here as I’m looking to add some in a weekly puzzle contest on my discord chess server.

idk tbh it was def outside of chess.com

3k4/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/N7/2K5 w - - 0 1 I had somebody give this to me. Good puzzle. fairly hard

i solved it in 10 seconds.  😁

i solved it in 30 seconds

i think its easier for intuitive players to spot these kinds of ideas

it was a good puzzle;  i just have a lot of experience with solving them & so the right motif happened to jump out at me i guess.

First try. The trick is to check whenever possible and set up a check whenever check is not possible.

i solved two 3800-rated puzzles in a row to finish off my 72 survival rush pb.  😎

done

??

Wouldn't say this puzzle is too difficult relatively, but certainly an interesting one! White to play.

Solution is 1. a7 f2 2. a8=Q f1=Q 3. Qe8+!! Nxe8 4. d8=N+!! Kf6 5. Ne4#

Hey! That's my puzzle! Thanks for playing!

3k4/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/N7/2K5 w - - 0 1

Gracias, amigo.